Fully self-consistent calculations of magnetic structure within non-collinear Alexander–Anderson model
https://doi.org/10.17586/2220-8054-2020-11-1-65-77
Abstract
An implementation of the non-collinear Alexander–Anderson model for itinerant electrons in magnetic systems is presented where self-consistency is reached for specified directions of the magnetic moments. This is achieved by means of Lagrange multipliers and a variational principle for determining the transverse and longitudinal components of the magnetic moments as well as the average number of d-electrons using direct optimisation. Various optimisation algorithms are compared and the limited memory Broyden–Fletcher–Goldfarb–Shanno algorithm is found to give the best performance. An application to antiferromagnetic Cr crystal is presented where spin-dynamics and curvature of the energy surface are calculated to compare results obtained with and without the constraints on the orientation of the magnetic moments.
Supporting agencies: This work was funded by the Icelandic Research Fund, the University of Iceland doctoral fund (AVI) and the Russian Science Foundation under grant No. 19-72-10138.
About the Authors
A. V. Ivanov
Saint Petersburg State University; Science Institute and Faculty of Physical Sciences, U. of Iceland
Russian Federation
Russian Federation
199034, Saint Petersburg
107 Reykjav´ık
P. F. Bessarab
Science Institute and Faculty of Physical Sciences, U. of Iceland; ITMO University
Ireland
Ireland
107 Reykjav´ık
197101 Saint Petersburg
H. Jonsson´
Science Institute and Faculty of Physical Sciences; Department of Applied Physics, Aalto University
Ireland
Ireland
107 Reykjav´ık
FI-00076 Espoo, Finland
V. M. Uzdin
ITMO University
Russian Federation
Russian Federation
197101 Saint Petersburg
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Review
For citations:
Ivanov A.V., Bessarab P.F., Jonsson´ H., Uzdin V.M. Fully self-consistent calculations of magnetic structure within non-collinear Alexander–Anderson model. Nanosystems: Physics, Chemistry, Mathematics. 2020;11(1):65–77. https://doi.org/10.17586/2220-8054-2020-11-1-65-77
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